A container of the above type comprises a cylindrical housing having a first axial end formed with an intake opening connected to a source of lubricant. The first axial end of the cylindrical housing is provided with an external thread for connecting with the source of lubricant. Particularly, but not exclusively, the source of lubricant may be a bearing.
Such a container typically comprises a piston slidably mounted inside the housing, which divides the container into a front compartment into which the intake opening opens and a back compartment that is delimited by a second axial end of the cylindrical housing. The piston can thus be moved back as the compartment fills until it reaches the second axial end of the container preventing further movement. The second axial end is covered with a cap having a vent hole. The second axial end and the cap are typically joined together through a threaded coupling.
A lubricant container of the above type is described in the patent document EP 2573444.
A lubricant container of the above type can be improved in many aspects. In particular:                the coupling between the second axial end of the container and the cap can be improved by making it easier the assembling and more difficult the disassembly,        the coupling between the second axial end of the housing and the cap requires threads to be provided both on the second axial end of the container and on the cap, i.e. further manufacturing steps are necessary after the manufacturing of the cylindrical housing and of the cap, which are both normally obtained by a moulding process,        in the container of the above described type, at service, an operator is not able to empty the container, particularly when the container is full of lubricant, i.e. when the piston reaches the second axial end,        the threaded coupling between the first axial end of the cylindrical housing and the source of lubricant does not allow an easy mounting or substitution of the lubricant container, particularly when the operator cannot visually see the mounting position,        further, the threaded coupling between first axial end of the cylindrical housing and the source of lubricant does not provide an efficient sealing.        